A study has shown that the age of a gene determines how fast they adapt.
In 1932, Sewall Wright introduced the metaphor of the “fitness landscape” model, where evolving genetic populations “walk” toward a fitness peak, just like a hiker slowly making its way to the top of the mountain. In 1998, Orr demonstrated that the further away a population is from its fitness peak, the larger the steps it makes.
One prediction of this theory is that recently evolved, or “young”, genes tend to accumulate more adaptive mutations with larger effects than older genes because they are further away from their fitness peak. This hypothesis was successfully tested and confirmed in a 2022 study.